Method of producing a layer of plastics material between two glass panes and apparatus for performing the method

ABSTRACT

A method of producing a layer of plastics material between two glass panes and an apparatus for performing said method, wherein the plastics material is filled in liquid form between the two glass panes which are in an inclined or vertical position and maintained parallel and sealed at their outer edges, are characterized in that the two glass panes are pressed against each other at their outer surfaces by one or a plurality of rotatable devices to achieve pressure guided in parallel and extending preferably over the total width of the glass panes, which pressure devices are movable along the total length of the glass panes, and that the pressure devices are moved at the curing rate of the plastics material from one end of the glass panes to the other end of the glass panes relative thereto.

The present invention relates to a method and to an apparatus forperforming the method of producing a layer or lamina of plasticsmaterial between the two glass panes, wherein the plastics material inliquid form is fed between the two glass panes being maintained paralleland sealed at the outer edges thereof and a pressure is exerted on thesurfaces of the glass panes.

Such methods and apparatus are already known. DE-AS No. 22 26 342, forexample, specifies a method of producing a laminated glass comprisingtwo glass panes bonded together by intermediate layer of self-curing,transparent plastics material capable of being cast, said two glasspanes with a spacer separating and sealing the glass panes only at theedges thereof, being leant in vertical position against a tiltable plateand the space between them being filled at least in part with the liquidplastics material, the plate together with the two glass panes is thentilted slowly towards the horizontal position whereby a bulge or bowingin the glass pane averted from said plate resulting from the pressure ofthe liquid plastics material in the vertical position is reformedwhereby the plastics material fills the whole space between the glasspanes until an opening provided in the spacer for the ventilation isclosed. The recession or reformation of the bulge of the glass pane mayalso be effected additionally by means of a suction cup connected by ahose to a subpressure source.

Furthermore, from DE-OS No. 27 28 762 a method is known of producing alaminated glass pane, wherein the space between two horizontal panesmaintained parallel to each other by a spacer is filled with a plasticsmaterial. Measures to avoid the tendency of the glass panes to bulgeoutwards and inwards, respectively, which is caused by the pressure ofthe plastics material filled in and by the weight of the upper glasspane, are not considered in said publication.

Another method of producing laminated glass panes is specified in DE-OSNo. 26 06 569. According to said method, the plastics material is filledinto the interspace between the two glass panes in the inclined positionand the curing proper takes place in the horizontal position.

Further, from DE-PS No. 27 37 740 a method is known of producing alaminated glass consisting of two glass panes and one intermediate layerwherein an already finished layer of plastics material is glued asintermediate layer between the glass panes, and the glass panes arepressed against the layer of plastics material by means of rotatablerollers in order to avoid gas bubbles in the adhesive lamina. Thismethod of bonding glass plates and intermediate layer is, however,expensive and requires, moreover, a pre-fabricated layer of plasticsmaterial.

CH-PS No. 574 371 relates to a sound-absorbing glazing in the form of alaminated body of two glass panes surrounding a layer of plasticsmaterial. In a method of producing such a laminated body the glass panesare placed in a water reservoir in the vertical position for filling inthe plastics material. In order to prevent the tendency of the glasspanes to bulge, the process is carried out with different water levelsdepending on the pressure ratios and thickness of the glass panes. Thismethod does not limit the hydrostatic pressure but compensates byhydrostatic counterpressure the continuously increasing hydrostaticpressure which is extraordinarily high in case of large glass panes. Theelaborate and complicated character of this method due to the largepressure-stable water reservoir is obvious and does, moreover, notguarantee that the opposing glass panes are plane-parallel, which isrendered still more difficult because, as it is known, self-supportingglass panes are not entirely vertical.

It is the object of the invention to provide a method which can beperformed with simple means and a simple device for performing saidmethod which allows the production of flawless panes of plasticsmaterial and/or laminated glass panes.

In the method according to the invention filling process and curingprocess are combined whereby a large number of technical problems areovercome as they occur e.g. when the glass panes are brought in thevertical position to render possible a good inflow of the plasticsmaterial and to avoid inclusions of air bubbles. With the filling andcuring process according to the invention a high static pressure whichwould destroy the necessarily soft sealing of the edges and would causea tendency of outward bulging of the glass panes is not built-up evenwhen the panes are set up vertically. The production of glass panes of auniform thickness and very large dimensions is guaranteed. It is noproblem to separate the finished sheet of plastics material from theglass panes when a plastics material is used which does not react withglass or when the inner surfaces of the glass panes are provided withseparating agents before the filling process is started. In particularthe method according to the invention gives the possibility of thecombined production of very long laminas of plastics material. Inparticular, it is possible to produce laminated glass panes by themethod according to the invention in a simple way and of high quality.Laminas of plastics material may be obtained up to any arbitrary fillinglevel which are flawless and free of air bubbles.

Due to the quick curing of the plastics material it is possible that thedevices to achieve a pressure (pressure devices) keep the glass panesseparated at an exact distance during the filling process, that a quickpolymerisation of the plastics material is initiated, and that theplastics material now solidifying has no flow properties anymore whichwould cause a bulging-out of the glass panes. For this purpose the pairof glass panes can be positioned vertically or inclined on a solidsupport and the uniform distance (between the glass panes) during thefilling process can be controlled from one side e.g. by means of acourse of rollers or drums. When a glass pane is in a preferred verticalposition, oppositely arranged devices to achieve pressure can also becarried along in conformity with the filling process whereby it is e.g.also possible to fill the interspace of bent glass panes. The methodaccording to the invention also allows a sandwich arrangement of morethan two glass panes at adjustable distances.

The apparatus according to the invention is a simple construction andrequires only substantially arbitrary devices to achieve pressure andmeans for moving said devices and/or glass panes to effect the relativemovement between glass panes and said devices at the curing rate of theplastic material.

It may be advantageous to hold the glass panes in an inclined positionduring the production process whereby the static pressure is reduced andthe total height of the arrangement is reduced to low dimensions also incase of large panes.

A further development of the invention is that the plastics material israpidly curable by intense external radiation. When a plastics materialis used which is curable by, for instance, intense ultravioletradiation, the curing rate may be determined quite exactly. In order toconsider production errors due to aging processes of the radiationsource, its intensity can be regulated.

A further development of the invention is that one or more radiationsources are located before or behind one of the two devices to achievepressure and are movable together with them. Depending on thesensitivity of the material to be radiated and its thickness the curingrate can be determined by switching on a plurality of light sourcesrespectively arranged between said devices.

A further development of the invention is that the plastics material isfed in in conformity with the rate of motion of the pressure deviceswhich are respectively guided in the area of the liquid surface of theplastics material. This allows that only the rate of inflow of theplastics material must be controlled when the rate of the pressuredevices and light sources is constant.

A further development of the invention is that the plastics material isfilled in and the devices to achieve pressure are moved such that saiddevices are always in the area of the liquid surface of the plasticsmaterial. A constant filling rate is assumed therefor and the rate ofthe pressure devices and of the radiation path is adapted to the liquidsurface of the plastics material. For example, when the liquid issupplied uniformly, the filling rate is halved when the interspacebetween the glass panes has been doubled.

A further development of the invention is that the plastics material iscurable by heat and that the heat may be supplied via the devices toachieve pressure. This heat supply must not be caused by intenseradiation, but a microwave apparatus incorporated for instance in a drumand travelling to and fro, if necessary, is adapted to heat quicklyfilled-in materials without heating the glass, and to initiate a curingprocess.

A further development of the invention is that the pressure devicesextend over the total width of the glass panes.

A further development of the invention is that the radiation source isarranged between two adjacent pressure devices so that in the area wherethe plastics material is still liquid the glass panes can be maintainedin position by one pressure device, is then hit by a, for instance,intense UV radiation, that then another pressure device follows, andthereafter, perhaps, another intense radiation, then another pressuredevice etc. This depends on the filling rate, the required radiationintensity, the radiation capacity of the lamps, as well as on the timerequired by the fed-in plastics material to lose its flow property.

A further development of the invention is that the devices to achievepressure and the radiation source are not movable but stationary andthat the unit of glass panes is passed therethrough in an inclined andvertical position, respectively. The production may be, for example, acontinuous production by guiding one pair of glass panes after the otherone through the positioning station and, e.g. through the radiationstation.

The devices to achieve pressure must not fulfill specific requirements.Besides drums and rollers hoses filled with liquid may be used whichhave a more gentle effect on the surface. In order to prevent the glasssurfaces from being scratched, it is also possible to provide aprotective sheet or film between pressure devices and glass panes.

The devices to achieve pressure may be provided alternatively also withpneumatic, hydraulic or mechanic (with spring action) control deviceswhich effect an exact pressure compensation over the total surface ofthe glass pane when the pressure devices are moved. It is also possibleto move air-cushion developing aggregates relative to the glass paneswhereby their surfaces are in no way damaged due to the non-contactpressure effect.

A further development of the invention is that it is also possible toprocess besides non-component plastics materials multi-componentmaterials. When surplus of plastics material (fat edges) occurs in theinterspace between the glass panes when the plastics material is filledin, it is possible to convey the liquid to be filled in by means of athin hose, for instance a sausage skin, into the interspace between theglass panes until up to the upper liquid level and to heave it (thehose) continuously up and outwards with the liquid level. The ratio ofprocessing time to curing time in the presently repeatedly used castresins which are mixed shortly before they are filled in isapproximately 1 : 10. Thus, it may be considered in conjunction with amixing apparatus that a processing period of 30 seconds is utilized toreach the interspace between the glass panes up to the surface of theplastics material from the proportioning means via the hose. Within aperiod of 5 minutes a curing has then occured here which is strongenough to at least eliminate the flowability of the material. When thepressure devices have a height of about 1 m it is possible to fill theinterspace between the glass panes in 15 minutes up to a height of 3 m.With the presently usual manufacturer's standard stock size for floatglass production of 6 m×3.21 m it would be possible to produce about 80m² per hour. With the present production methods a very complicatedmachinery and, in particular, very much space is required to produce aglass pane of 6 m×3.21 m. A substantial advantage of the invention isthat the above production is possible on a base surface of e.g. only 10to 15 m². The halls in glass-processing installations have usually therequired height of, like in the present case, about 4 m--without a pit.

A further development of the invention is that the vertically positionedor inclined glass pane can be filled with prepared air or a differentgas before the liquid plastics material is filled in, which gas is thenexpelled by the flowing-in and ascending liquid. According to one'sdesire, the lattice-like polymerisation of plastics material and glasscan, in this way, be improved and deteriorated, respectively.

A further development of the invention is that the temperature of theglass pane and of the liquid plastics material to be filled in isdifferent. When, for example, the plastics material to be filled in isheated, a precipitate is formed immediately at the upper edge of theliquid column on the surface of the glass which counteracts the adhesionof plastics material to the glass.

The invention will be explained hereinafter by means of the drawings,wherein

FIG. 1 illustrates an embodiment of the apparatus according to theinvention,

FIG. 2 illustrates another embodiment of the apparatus according to theinvention, and

FIG. 3 illustrates an embodiment of the apparatus according to theinvention wherein a plurality of drums and radiation sources areprovided.

FIG. 1 shows a vertically positioned pane unit comprising two glasspanes 1, 1 and a spacing piece or a spacer 2 which are held in positionby pressure devices in the form of drums or rollers 4 running before andbehind (said panes) when liquid plastics material 3 is fed in theinterspace 5 between said panes. Especially with a vertical arrangementit is possible to produce pane units of more than two panes 1 at thesame time, by filling the interspaces between the glass panessimultaneously with liquid plastics material 3 which requires specialattention for example when the distances between the glass panes aredifferent. When the liquid level is maintained always somewhat above thedrums, the panes are pressed uniformly against the drums by the staticpressure. Multiple glass panes may, however, also be produced one afterthe other by putting-on another pane and increasing the distance of theholding means to each other.

FIG. 2 illustrates a table supporting the pane unit and the rollercourse or assembly is moved together with a curing device provided withradiation sources over the glass surface concurrently with the fillingprocess. During the filling process said table may be positionedvertically or it may be inclined depending on the flowability of theplastics material, on the thickness of the pane or, e.g. also on theavailable headroom. When the table is at an inclined position theuppermost glass pane is sagging which can easily be compensated bymaintaining the filling degree of the glass pane at a somewhat higherlevel than the concurrent drum and radiation unit, the static pressurepressing the upper glass pane against the roller assembly running abovethus guaranteeing an optimum uniform thickness. Contrary to theconventional methods the quantity filled in must not be determinedprecisely beforehand but the completely filled interspace 5 directs thatthe filling process can be stopped.

FIG. 3 illustrates a stationary drum and radiation unit through whichthe glass panes are passed while being filled. The position of said unitis adjusted to be vertical or inclined depending on the consistence ofthe liquid plastics material.

Contrary to the embodiments according to FIGS. 1 and 2 the latterembodiment does not require a device for moving the devices to achievepressure. Instead a moving device for moving the glass pane unit must beprovided. As both moving means may be implemented in any way desired, itwas renounced to illustrate them.

The embodiments were explained in connection with the use of drums asdevices to achieve pressure. Meanwhile, however, rotatably mountedrollers turned out to be good in practice. However, also a number ofother pressure devices such as those referred to at the beginning areimaginable without cutting down the advantageous effect of the apparatusaccording to the invention.

I claim:
 1. A method of forming a sheet of plastic material in a spacebetween first and second panes, each having a width and a length and anouter surface and inner surface, sealed along the length thereof,wherein the improvement comprises:(A) feeding liquid plastic materialinto the space between the inner surfaces of said panes to form a risinglevel of plastic material therein; (B) applying pressure adjacent therising level of liquid plastic material by pressure application meansextending over about the width of the outer surface of said first pane;(C) curing said plastic material and continuing the application ofpressure for about the length of said first pane as relative movement ofsaid first and second panes and said pressure application means iseffected at about the rate of curing of said plastic material.
 2. Themethod of claim 1 wherein pressure is applied by pressure applicationmeans behind and adjacent the rising level of liquid plastic material.3. The method of claim 1 wherein relative movement of said panes andsaid pressure application means is effected by moving said panes.
 4. Themethod of claim 1 wherein relative movement of said panes and saidpressure application means is effected by moving said pressureapplication means.
 5. The method of claim 4 wherein the rate of movementof said pressure application means is adapted to a given rate of feedingliquid plastic material into the space between said panes.
 6. The methodof claim 1 wherein relative movement of said panes and said pressureapplication means is effected by moving said pressure application meansin the direction of the rising level of liquid plastic material.
 7. Themethod of claim 1 wherein said plastic material is cured by heat.
 8. Themethod of claim 1 wherein said plastic material is cured by radiation.9. The method of claim 1 wherein said panes are at an angle to thehorizontal.
 10. The method of claim 9 wherein said panes are verticalduring the feeding of liquid plastic material into the space betweensaid panes.
 11. The method of claim 1 wherein said pressure applicationmeans includes means for curing said plastic material.
 12. The method ofclaim 1 wherein said liquid plastic material is fed into the spacebetween said first and second panes without wetting the inner facesthereof.
 13. A method of forming a sheet of plastic material in a spacebetween first and second glass panes, each having a width and a lengthand an outer and inner surface, sealed along the lengths thereof,wherein the improvement comprises:(A) feeding liquid plastic materialinto the space between the inner surfaces of said panes to form a risinglevel of liquid plastic material therein; (B) applying pressure overabout the width of the outer surface of said first pane by:(i) firstpressure application means moving adjacent and behind said rising levelof liquid plastic material, and (ii) second pressure application meansspaced from and behind said first pressure application means; (C) curingsaid plastic material during the continuing application of pressure bymoving said first and second pressure application means over the lengthof the outer surface of said first pane at about the rate of curing ofsaid plastic material.
 14. The method of claim 13 wherein means forcuring said plastic material is mounted between and adjacent said firstand second pressure application means and moves therewith to cure saidplastic material.
 15. The method of claim 13 wherein said liquid plasticmaterial is fed into the space between the inner surfaces of said panesin conformity with the rate of movement of said pressure applicationmeans.
 16. Apparatus for forming a sheet of plastic materialcomprising:(A) a first pane having (1) an outer surface, (2) an innersurface, (3) a length, (4) a width, (B) a second pane having(1) an innersurface, (C) spacing means positioned between the inner surfaces of saidfirst pane and said second pane to form a space therebetween, (D)delivery means for feeding liquid plastic material to the space betweenthe inner surfaces of said first and second panes to form a rising levelof liquid plastic material; (E) pressure application means operativelyassociated with said first pane for exerting pressure on the outersurface thereof adjacent the rising level of liquid plastic material;and (F) drive means for effecting relative movement of said first andsecond panes and said pressure application means to cause pressure to beexerted adjacent the rising level of liquid plastic material on theouter surface of said first pane for about the length thereof.
 17. Theapparatus of claim 16 wherein said pressure application means extendsabout the width of the outer surface of said first pane.
 18. Theapparatus of claim 16 wherein curing means is positioned adjacent saidpressure application means.
 19. The apparatus of claim 16 wherein saidcuring means is located within said pressure application means.
 20. Theapparatus of claim 16 whrein said pressure application means is in theform of a rotatably mounted cylindrical device.
 21. The apparatus ofclaim 16 further including pressure application means operativelyassociated with said second pane for exerting pressure on the outersurface thereof adjacent the rising level of liquid plastic material.